Sterilized catgut thread.



HUGO SCHMIDT, OF BADEN, GERMANY. I

STERILIZED CATGUT THREAD.

Specification 0'1 Letters Patent.

7 Patented May 12, 1908.

Application filed April 2, 1906. Serial No. 309,560.

To all whom it may concern:

Be it known that I, HUGO SCHMIDT, a subject of the German Eni eror, and resident 0 Mannheim R6 r. 6b., Baden, Germany, have invented a Sterilized Catgut Thread, of which the following is a specification.

The methods hitherto employed for ster ilizing the catgut threads commonly used in surgery for fastening ligatures and for sewing have proved unsatisfactory, either because the catgut has not been completely freed from fatty substances, and is conse quently not thoroughly permeated by the sterilizing liquid or because the treatment to which the catgut is subjected renders it friable or otherwise impairs its uality-and consequently diminishes its' utility.

Among the various means for sterilizing catgut already proposed is the employment of iodin solution. Catgut, however, when immersed in an aqueous solution of iodin in iodidof potassium curls up and crumples; In order to obtain any thread whatever it is necessary, before subjecting the catgut to the action of the iodin solution, to wind it upon a glass bobbin, and even when thus wound catgutprepared in the manner referred to, in a very short time not exceeding from 2 to 3 weeks becomes so friable, and brittle as to bepractically worthless.

Now the above mentioned disadvantages can be entirely obviated by the addition of formaldehydeto the aqueous solution of iodin in iodid of potassium and even ordinary catgut threads, in the condition .in.

which they are placed' on the -market, when immersed in such a solution of formaldehyde and iodin completely retain their form and flexibility while as-proved by bacteriological tests, they at "the same time become completely sterilized:- I

The process to which this invention relates moreover possesses the further advantage that catgut sterilized in this manner, can,

when removed from the sterilizing solution, be dried, and kept for any length oftime in a sterilized packing without losing its flexibility. It has not heretofore been possible by means of an iodin solution to obtain catgut that is oughly sterilized. The German Patent No. 127515 it is true, describes a process for plieparing an antiseptic by treatlng elatin st With a solution of iodin in iodid o potassium and then with formaldehyde. Accordin to at once durable, dry, and thorthe process described in the said spec' cation, however, as therein distinctly stated, the formaldehyde is used only for hardening the, gelatin, 'and that is, moreover, obvious from the further statement that for the formaldehyde there may be substituted other similar substances, as for instance, chromalum. In the process to which this invention relates the function of the formaldehyde is however of a totally different character. When a catgut thread is treated with formaldehyde it swells and after being removed from the solution and dried it soon becomes brittle and friable, and, as the formaldehyde evaporates it loses its sterility and is thus rendered useless for the purpose in question.

If, however the formaldehyde is added to the solution of iodin, the result as already stated, is 'quite different, the threads then completely retainin their form and flexibility, while their steri 'ty is maintained by the action of the iodin, evenafter the formaldehyde has evaporated, The combined use of iodin solution and formaldehyde thus produces a 1distinctly novel and characteristic resu t. J 1

In carrying out the invention a concentrated stock solution is prepared b dissolv-. ing one art by we' ht of iodin an one part by 'weig t of-iodid o potassium in three parts by weight of distilled water, to which there is added from 0.4 to 0.5 part. by weight of a 40 I per cent. solution of formaldehyde. Is is advantageous but not essential to add one part by welght of glycerin. The solution actually used is prepared by diluting the stock solution by the addition for each part of iodin therein, of 100 parts of'cold water that has previously been; boiled. 'The crude catgut threads are immersed in this solution for from three to five days and are read for use in from 5 to 8 days. They may be removed from thesolntion immediately before their use or they ma be and ke t readyv to handin-a suita le sterilized enve op.

What I claim as my invention and desire to I In testimony .Whereof I have hereunto secure by Letters Patent is A I signed my name to this specification in the 10 A11 sterilized catgut threiad impregnafted presence of two subscribing Witnesses. Wit an antise tic com oun consistin 0 an 1 5 aqueous solutihn of io din in iodid of otas- I HUGO SCHMIDT sium containing formaldehyde and a apted itnesses: to remain permanently pliable and tough and H. W. HARRIS, to retain its form. Jos. H. LEUTE. 

